A U.N. nuclear inspector says the date when North Korea shuts down it nuclear reactor depends on discussions between Pyongyang and five other countries that signed a disarmament agreement.

International Atomic Energy Agency official Olli Heinonen said Saturday in Beijing his negotiations in North Korea have clarified how the agency will monitor the closing of the Yongbyon nuclear facility.

Heinonen and other nuclear inspectors ended a tour of the nuclear facility Friday, saying they reached an "understanding" with North Korea on how they will verify and monitor the shutdown of the reactor. They did not provide details.

North Korea agreed to shut down its nuclear reactor earlier this year in talks with the United States, South Korea, Japan, China and Russia.

Those six-party negotiations are expected to resume some time next month.

The IAEA's trip to North Korea is the first time U.N. inspectors have visited the country since North Korea expelled the group in 2002.

The inspectors say the reactor is still operating, and that they were able to visit all the places originally intended for inspection.

In exchange for closing its nuclear reactor, North Korea will receive fuel aid.

Some information for this report was provided by AFP, AP and Reuters.